/*
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package box.data.pri.hessian.v4_0_7.burlap.server;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;

import javax.servlet.GenericServlet;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import box.data.pri.hessian.v4_0_7.burlap.io.BurlapInput;
import box.data.pri.hessian.v4_0_7.burlap.io.BurlapOutput;
import box.data.pri.hessian.v4_0_7.services.server.Service;
import box.data.pri.hessian.v4_0_7.services.server.ServiceContext;


/**
 * Servlet for serving Burlap services.
 */
public class BurlapServlet extends GenericServlet {
    private Class<?> _apiClass;
    private Object _service;

    private BurlapSkeleton _skeleton;

    public String getServletInfo() {
        return "Burlap Servlet";
    }

    /**
     * Sets the service class.
     */
    public void setService(Object service) {
        _service = service;
    }

    /**
     * Sets the api-class.
     */
    public void setAPIClass(Class<?> apiClass) {
        _apiClass = apiClass;
    }

    /**
     * Initialize the service, including the service object.
     */
    public void init(ServletConfig config) throws ServletException {
        super.init(config);

        try {
            if (_service == null) {
                String className = getInitParameter("service-class");
                Class<?> serviceClass = null;

                if (className != null) {
                    ClassLoader loader = Thread.currentThread().
                                         getContextClassLoader();

                    if (loader != null) {
                        serviceClass = Class.forName(className, false, loader);
                    } else {
                        serviceClass = Class.forName(className);
                    }
                } else {
                    if (getClass().equals(BurlapServlet.class)) {
                        throw new ServletException(
                                "server must extend BurlapServlet");
                    }

                    serviceClass = getClass();
                }

                _service = serviceClass.newInstance();

                if (_service instanceof BurlapServlet) {
                    ((BurlapServlet) _service).setService(this);
                }
                if (_service instanceof Service) {
                    ((Service) _service).init(getServletConfig());
                } else if (_service instanceof Servlet) {
                    ((Servlet) _service).init(getServletConfig());
                }
            }

            if (_apiClass == null) {
                String className = getInitParameter("api-class");

                if (className != null) {
                    ClassLoader loader = Thread.currentThread().
                                         getContextClassLoader();

                    if (loader != null) {
                        _apiClass = Class.forName(className, false, loader);
                    } else {
                        _apiClass = Class.forName(className);
                    }
                } else {
                    _apiClass = _service.getClass();
                }
            }

            _skeleton = new BurlapSkeleton(_service, _apiClass);
        } catch (ServletException e) {
            throw e;
        } catch (Exception e) {
            throw new ServletException(e);
        }
    }

    /**
     * Execute a request.  The path-info of the request selects the bean.
     * Once the bean's selected, it will be applied.
     */
    public void service(ServletRequest request, ServletResponse response) throws
            IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;

        if (!req.getMethod().equals("POST")) {
            res.setStatus(500, "Burlap Requires POST");
            PrintWriter out = res.getWriter();

            res.setContentType("text/html");
            out.println("<h1>Burlap Requires POST</h1>");

            return;
        }

        String serviceId = req.getPathInfo();
        String objectId = req.getParameter("id");
        if (objectId == null) {
            objectId = req.getParameter("ejbid");
        }

        ServiceContext.begin(req, serviceId, objectId);

        try {
            InputStream is = request.getInputStream();
            OutputStream os = response.getOutputStream();

            BurlapInput in = new BurlapInput(is);
            BurlapOutput out = new BurlapOutput(os);

            _skeleton.invoke(in, out);
        } catch (RuntimeException e) {
            throw e;
        } catch (ServletException e) {
            throw e;
        } catch (Throwable e) {
            throw new ServletException(e);
        } finally {
            ServiceContext.end();
        }
    }
}
